Control device for alarm mechanism



Dec. 20, c HOWARD CONTROL DEVICE FOR ALARM MECHANISM Filed May 19, 1931 2 Sheets-Sheet l jeiz;

Dec. 20, 1932. I c. P.'HOWARD 1,

CONTROL DEVICE FOR ALARM MECHANISM Filed May 19, l931 2 ShQGtS-SIIQQL 2 Patented Dec. 20, 1932 umreo STATES" or Pics;

I CLIFTON P. HOWARD; OF WORG 'ESTER-Q MASSACHUSETTS, ASSITLGNOB)" TO ROCKWOOD SPRINKLER COMPANY O F MASSACHUSETTS, A CURPORATIONOF"MASSACHUSETTS' GONTROII DEVICE EOE ALARM MECHANISM Application; and Ma ne;-

V This. invention relates to mechanism for. soundinganialarm.atsome distantpoint upon an excessive risev in atmospheric temperature.

I in; an; area: protected by; the alarm mechanism. Such alarmimechanism may beused in. places-Where the opening; of a sprinkler headicannoti be permitted,or it may be used as additional; protection. y I

It isthe object ofmy. inventionto provide.

animproved control device for such an alarm mechanism; so. designed that ,it may beheld. inin-ormal condition by. aheat-releasable fusible link. h

- A further-object of my inventionis to. so construct my improved control devicethat it" maybe assembledonthe cover plate of an ordinary jnnction box..

My invention further relates-tov arrangements and combinations ofuparts which willbe: hereinafterdescribed and: more particularly pointed out. in the appended claims.

v A- preferredform of the invention is shown inthedrawings in which Fig.1 is :asideelevat'on, partly in section, showing'aljunction; box with my improved control; device mounted thereon Fig. 2Zis-ap1an view ofithe control device, taken along the line 2-2 iii-Fig. 1,; I

- Fig. 3 is a bottomview ofithe device, lookinm-inithe direction of the arrow 3 in-Fig,.1.;

- igi. 4e isa detail sectional: view, taken along the line iniFig'. 1;

"Fig; 5' isa sectional side. elevation of the control device; 1

Fig; 6 is'a" sectionalabottom view, taken along the line 6,-6 inzFig. 5; e

Figs 7 's a sectional side elevation, taken along the line 7.-7- in Fig. 6; I

Fig; 8:is a: View similar to. Fig; 5 but show ingzthe parts released, and

Fig; 9 is a: detail view showing a. slightly modified construction. 1

Referring to the drawings, 1: have; shown ajunction box 10 of aflusualzcommercial form,

liavingcondnits 1'1 and 12: connected thereto.

Fig 5,. with 1931. Serial No. 538,494..

Trl ie'cover plate 13 is formed With/a de-- 50 pressed. or cup-shaped portion 15 (Fig. 5) having a slot 16; (Fig. 4); in its lower. end

. face or. bottom. The coverplate 13 is also.

providedwitha shoulder 18 (Fig. 8) which supports a disc20 ofi'nonz-conducting mate rial. Gontactmembers 2l and 22 are mount edw-on thedisc 20-and areconnected to wires,

23 and24 in-the junction box .10. I

A heavy lJ-shaped spring30 is secured to thedisc20 by screws 31 (Fig; 7 andthein 80 ner offset ends of the, contact members 21. and 22 a are extended toward each other and. are; positionedin .the'opening between the ends of thespring; 30.

Toggle levers 33 311161534; extend throu h the slotlfi -in the cover- 13, as indicatedin .ig...8; I i

The levers 33and 34-. are notched in their out;- er. base portions, as indicated at 35, to receive the ends of the spring 30.v The base portion ofithe lever 34: is also notched at 36 to receive the projecting corner 37 ofthe lever 33.

. Contact plates 38: and 39 project. inward from the base portions of the toggle levers 33 and.341-to positions adjacent the ofiset. ends 7 of. the contact. members 21' and 22.

The outer ends-of the togglelevers 33and 34: are provided v with hooksshaped portions "4:0:andwithprojections 11.v The hook-shaped portions. are. designed to extend through openings 43 (Fig. linkill by which the toggle members are. normally maintained in the position shown in the contact plates 38' and 39 spaced away from the contactmembers 21 3) in the ends ofia fusible 8 andi22n Theprojections 41 preventinward displacement of the link.

Thefusible link L. may. be of any usual or.- commercial construction and is shown herein as comprising a: flat link member 50 (Fig; 8) and) bracket member'51and; a lock- 9 ing member 52. The members and 51 are normally positioned face to face, as indicated in Fig. 5, and one end of the locking member 52 extends through aligned slots in the members 50 and 51.

The extreme outer end of the locking member 52 is preferably hook-shaped, as indicated at 54 in Fig. 8, and extends through a slot in the extreme outer end portion of the bracket member 51, where it is secured by a portion of low-melting alloy or solder 56. The alloy or solder 56 which holds the member 52 in locking position is in compression or shear and not under tension.

The fusible link herein shown forms no part in itself of my present invention and is described in detail in the copending application of George I. Rockwood, Serial No. 520,041, filed March 4:, 1931.

When the parts are assembled as shown in Fig. 5, the wires 23 and 24 are connected to the contact members 21 and 22 by binding screws 60, and the cover plate 13 is then secured to the junction box 10. As many of these control devices may be provided as is necessary to fully protect the defined area.

The control devices D, when designed for use on an open circuit system as indicated in Figs. 1 to 8, will be mounted in parallel between the wires lV (Fig. 1) of the alarm circuit. On an excessive rise in temperature, the solder on the fusible link will melt, allowing the parts of the link to separate, as shown in Fig. 8, and the spring 30 will swing the toggle levers 33 and 3a to the position also shown in Fig. 8, causing the contact plates 38 and 39 to firmly engage the contact members 21 and 22, thus closing the circuit be tween the wires W and causing the alarm to sound. The toggle levers 33 and 34 are formed of bronze or other suitable metal, so that the circuit is completed through the contacting portions of the toggle levers and also through the spring 30.

If the device is to be used on a closed circuit system, the contact members 21" and 22 (Fig. 9) are spaced outside of the contact plates 38 and 39, instead of between the plates, so that they are engaged by the contact plates when the toggle levers are secured in normal position by the fusible link.

\Vhen the levers are released, the plates 38 and 39 move inward, as previously described, and by such movement are separated from the contact members 21" and 22 breaking the normally closed circuit. Otherwise the construction for closed circuit operation is identical with that for open circuit operation.

Having thus described my invention and the operation thereof, it will be seen that I have provided a very simple and reliable control device adapted to be assembled and supported on the cover plate of an ordinary junction box, and adapted to be easily installed in 1 the wiring system of an alarm mechanism and at as many points in said wiring s stem as may be desired. The type of fusible link herein described is very quickl responsive to a change in temperature and my control device when used in conjunction with this quickly res )onsive fusible link is extremely reliable an accurate.

Having thus described my invention and the advantages thereof, I do not wish to be limited to the details herein disclosed, otherwise than as set forth in the claims, but what I claim is 1. A control device for alarm mechanism comprising a non-conductin support, contact members mounted on sai support, a air of toggle levers having portions adap to engage saidoontact members, a spring having its ends in engagement with said levers and forming the entire and floating support for said levers, said spring tending to move said levers to change the operative relation of said lever portions and contact members, and heat-releasable means normally preventing such movement of said levers by said spring.

2. The combination in a control device as set forth in claim 1, in which the outer corner edges of the base portions of said two tog le levers are notched to receive the inwardly directed ends of said s ring, and in which the inner corner edge of t e base portion of one of said levers is notched to receive the inner corner edge of the base portion of the other toggle lever.

3. A contact device for alarm mechanism comprisin a cup-shaped support, a non-conducting plate mounted in said support but spaced from the bottom thereof, a heavy U- shaped spring mounted on said late within said cup-shaped support, a pair of spaced contact members mounted on said plate, a pair of toggle levers engaged with each other and with the ends of said spring and entirely supported by said spring, said levers having portions adapted to engage said contact members, and heat-releasable means restraining movement of said levers by said spring to change the operative relation of said levers and contact members.

4. A contact device for alarm mechanism comprisin a cup-shaped support, a non-conducting pTate mounted in said support but spaced from the bottom thereof, a heav U- shaped spring mounted on said plate within said cup-shaped support, a pair of spaced contact members mounted on said plate and having portions positioned within the curve of said spring, a pair of toggle levers having portions adapted to en age said contact members, and heat-releasa 1e means restrainin movement of said levers by said spring, said levers when released being moved by said spring to change the operative relation of said levers and contact members. 7

5. The combination in a control device as set forth in claim 4, in which the cup-shaped support has a slotted bottom, and in which portions of the toggle levers extend outward through said slot to receive and support said heat-releasable means.

6, The combination in a control device as set forth in claim 4, in which the heat-releas able means comprises a fusible link connect ing the outer ends of said levers and formed in separate parts normally held together by a low-melting fusible alloy.

In testimony whereof I have hereunto affixed my signature CLIFTON P. HOWARD. 

